Amyas Morse, head of the NAO, said: “We have seen almost three decades of change to NHS commissioning.

“It would be a huge waste if in five years’ time NHS commissioning is undergoing yet another cycle of reorganisation resulting in significant upheaval.”

He added: “The current restructuring of Clinical Commissioning Groups must deliver balanced and effective organisations that can support the long-term aims of the NHS and deliver a much-needed prolonged period of stability.”

A period of stability would allow commissioning groups to focus on transforming and integrating health and care services rather than on reorganising themselves, the report said.

Since CCGs replaced primary care trusts in April 2013, there have been eight formal mergers, reducing their numbers from 211 to 195 in April this year. Further mergers are expected.

The report also highlighted an increasing number of NHS commissioning bodies in England were exceeding their planned expenditure.

A total of 75 of 207 (36%) CCGs went over their budgets in 2017-18, the NAO noted. The total overspend across the groups was £213m.

This compared to 57 CCGs over spending on their budgets in 2016-2017 and 56 in 2015-2016.

“Many CCGs are struggling to operate within their planned expenditure limits despite remaining within their separate running cost allowance,” the report warned.

Increased pressures, the uncertain futures of CCGs and a lack of access to training and development were cited as reasons for the continuing issue of commissioning bodies being unable to attract and retain high-quality leaders.

Even though “both NHS England and the CCGs stressed [to the NAO] the importance of high-quality leadership”.

The watchdog also warned with further mergers there was “a risk that working across greater areas will make it more difficult for CCGs to design local health services that are responsive to patients’ needs”.

The total net expenditure of CCGs in England in 2017-18 was £81.2bn with net running costs at £1.1bn. Staff costs made up 57% (£693 million) of CCGs’ running costs, the NAO noted.

A 10-year long-term plan for the NHS and how it will spend an extra £20.5m a year was expected to be released by the end of this year.

2015 Public Finance. Public Finance is published on behalf of the Chartered Institute of Public Finance and Accountancy by Redactive Publishing Ltd. All rights reserved. Reproduction of any part is not allowed without written permission. Redactive, 17-18 Britton Street, London, EC1M 5TP